1. Field of the Invention
The present invention relates to a developing unit for developing an electrostatic latent image by adhering a developer on the electrostatic latent image, used in an image forming device such as a copying machine, a printer and a facsimile machine.
2. Description of Related Art
An image forming device carries out an image forming process by adhering a developer (toner) on an electrostatic latent image carrier on which an electrostatic latent image is formed. Accompanying the image forming process, the developer is consumed and a remaining amount of the developer decreases. Therefore, the developer is required to be replenished as needed. Accordingly, a developing unit is provided removably with respect to the image forming device so that when necessary, the developing unit can be removed from the image forming device to replenish the developer or to replace the developing unit.
In general, a gripper is provided on the developing unit so that the developing unit can be inserted and removed easily. Various conventional improvements on the gripper have been proposed. For example, according to one conventional improvement, an auxiliary tank of the toner also functions as the gripper. According to another conventional improvement, a concave part is formed on an upper part of an upper frame of a process cartridge in a longitudinal direction so that an operator's finger can be placed in.
When the developing unit is inserted removably in the image forming device as described above, the developer can be replenished in the developing unit and the developing unit can be reused. However, if developer that is noncompliant with the image forming device is replenished in the developing unit and the developing unit is reused, there are cases in which the developer causes a negative influence on the image forming device. Therefore, a countermeasure is required for preventing undesired developer from being replenished in the developing unit.
Accordingly, there is a demand for a developing unit which prevents the developer from being replenished easily in the developing unit by a simple structure using the gripper generally provided on the developing unit.